Caster wheel fork



Dec. 8, 1942. K A E R, SCUDDER E1- AL 2.3045378 QASTER WHEEL FORK Filed han. 16. 1942 ATTORNEYS Patented Dec. 8, 1942 UNITED STATES PATENT GFFICE Sherman, Palmer, Mass.,

Palmer, Mass.,

Jarvis, Inc., Massachusetts assignors to Jarvis & a corporation of Application January 16, 1942, Serial No. 426,950

3 Claims.

invention relates to casterwheel yforks and in particular is concerned with the fabrication of a fork from pressed steel, for the larger, heavier types of caster wheels which have in general been provided heretoforewith forks of malleable cast iron.

A primary object of this invention is to make a sturdy and more serviceable fork assembly Without the necessity for having castings of malleable iron made especially for this purposeY Furthermore, the new fork herein disclosed can be made entirely from flat bar and sheet metal This manufacturing costs.

The principal object in the development of this fabricated steel fork is due to the present system of priorities in this country. Because of it the necessity arose of finding Ways and means of continuing the manufacture of casters with such materials as were available and without the former convenience of usual facilities for obtaining prefabricated parts. In this particular instance prior art forks had been manufactured from malleable iron castings, the head and legs being cast integral in one unitary structure. This national defense. Applicants in their efforts to provide a substitute at nrst devised a fabricated unit comprising a cylindrical head formed of a short section of heavy Wall tubing to which the fork legs were separately welded. While this satisfactory from a structural standpoint, applicants continued their efforts r along this line of improvement, particularly with a view to a reduction in costs without loss of efliciency or serviceability and eventually developed the particular form of the invention shown in the accompanying drawing.

Another advantage over the prior` art fork is thefork head with bearing Referring more particularly to the drawing, our new fork construction is fabricated as fole lows: Preferably two semi-cylindrical pieces, one of which is seen in perspective in Fig. 3, are cut and shaped from a length of ilat bar metal into a half circle, making a shell I. They may be formed by a cold press into this shape. Two of such shells `I and la are adapted to coact in encircling oppositely facing ball bearing cup members 5 and 5a on caster stem 2 and serve as a barrel-like head for the. fork. .As seen in Fig. 4, the shell pieces are preferably arranged with the slight gaps 3, 3a formed between their adjacent edges, located at opposite sides ofthe head and on a transverse axis of the fork. These gaps 3, 3a are closed wholly or partially as will be later explained. The barrel-like head may in some cases be formed of a single nat piece bent around to provide a cylinder with a single gap. However, the operations are simpler and less costly when the head is made of two shell pieces as described.

The shells l, la are adapted to t at their upper and lower edges between outwardly projecting rims 4 and 4a 0f said cup members Sand 5a, and the shells are purposely made Wide enough to hold the cup members in spaced apart relation on stem 2 as shown. The cup members 5 and 5a are adapted to cooperate in the usual manner with cone members 'l and la and interposed balls 6 and 6a to form the usual ball bearing assemblies for the swiveling movement of the caster on its stem. At the top and bottom of the barrel-like headformed by the shells, the bearings are capped by washers. At the top, the washer 8 abuts a shoulder 9 on the stem 2 and at the bottom, the washer 8a is held by a slotted hex nut l threaded on the stem. By tightening the slotted hex hut lil the ball bearings are adjusted and securely held in their spaced position on stem 2. When clamped in position the cup members 5 and 5a rotate with the shell pieces l and la and the cone members 'I and 'la rotate with the stem during the swiveling movement of the head. Lubricating means for the .bearings are provided by the grease fitting l l in the opening l2 Vat a central spot in one of the shells la.

Legs I4 and Ma (see Fig. 5) for the head are formed by stamping and cutting pieces from a length of flat sheet steel. They are positioned so that their upper ends bridge each of the gaps 3 and Saand overlap an adjacent portion of each of the two shells. To this end the metal at the top of leach leg has been shaped to lt the curvature of the shells and as indicated in Figs. 1 and 4, they are welded directly to the head. As shown, each leg such as I4 in Fig. 1, is joined to the adjacent shell pieces I` and la by a welding seam which extends along one side edge 11a. of the leg, along the top edge I'lb, and along the other side edge I1c, which edges are contiguous to said shell pieces. The top welded seam IIb crosses the gap such as l3a and partially fills it. The remainder of said gaps 3 and 3a. exposed above their respective legs may be completelyV lled by welding if desired to keep out dust and dirt and present a neat appearance. The entire gaps 3, 3a could be welded before application of the legs or they could be individually welded and the legs placed otherwise. However, by welding the legs in the manner indicated over the gaps the `head structure is more economically fabricated without any sacrice of strength and in a manner to give a very neat appearance.

The flat steel construction of the depending legs is held securely by the welding to the shells and together with the head thus formed presents a sturdy and long lasting fork in which a wheel I6 can be mounted for use as a heavy duty caster. It will be noted in Fig. 2 that the two ball bearing assemblies are separated to form a reservoir of appreciable size for grease. In providing the spacing as indicated between the two bearings, the parts may be effectively supplied with lubrication for lasting over a long period of time without further attention.

What we claim is:

1. A caster fork comprising a barrel-like head and a pair of legs depending therefrom, said head being adapted to receive the caster stem,

ball bearings carried within said head for the swiveling movement of said stem, said head comprising two semi-cylindrical shell pieces with gaps between adjacent edges of said shell pieces at opposite sides transversely of said head, each of said legs having its upper portion arranged to` engage against the side of said barrel-like head over an area of contact which bridges one of said gaps between the semi-cylindrical shell pieces, each'leg being fastened to said shell pieces across the gap between the same by a welding seam extending along the side edges and top edge of said leg which are contiguous to said shell pieces.

2. A caster fork comprising a barrel-like head and a pair of legs depending therefrom, said A head being adapted to receive the caster stem, a pair of spaced apart ball bearing assemblies carried within said head for the swiveling movement of said stem, said ball bearing assemblies comprising upper and lower oppositely facing cup members each with a ange rim overlying the upper and lower edges of said head respectively, said head comprising two semi-cylindrical shell pieces having gaps formed between adjacent edges of said shell pieces at opposite sides transversely of said head,`each of said legs having its upper portion arranged to engage against the side of said barrel-like head over an area of contact which bridges one of said gaps between the semi-cylindrical shell pieces, each leg being fastened to said shell pieces across the gap between the same by a welding seam extending along the side edges and top edge of said leg which are contiguous to said shell pieces.

3. A caster fork for a caster wheel having a barrel-like head comprising two semi-cylindrical shell pieces adapted'to receive between them a caster stem, vertically spaced apart ball bearing assemblies mounted on said stem and within said head, one of said shell pieces having a grease fitting set therein between said two ball bearing assemblies, and a pair of legs formed at their upper ends to lit the cylindrical contour of said shells, each of said legs having its upper portion arranged to engage against the side of said barrel-like head over an area of contact which bridges Vone of said gaps between the semi-cylindrical shell pieces, each leg being fastened to said shell pieces across the gap between the same whereby the two shell pieces and the two legs are joined together as one integral member serving as a fork for the caster wheel.

ELIOT R. SCUDDER.

WILFRED E. SHERMAN. 

